This application claims the benefit of Korean Patent Application No. 2001-78670 filed on Dec. 12, 2001, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a disk clamping apparatus for a disk player.
2. Description of the Related Art
Generally, a disk player is an apparatus which records/reproduces information on/from a recording medium such as a CD, a CD-ROM, or a DVD. FIG. 1 shows a conventional disk player having a deck base 40 which includes a hinge connected to a housing (not shown) so as to have the deck base 40 rotate in a vertical plane, a deck plate 20 under which predetermined clampers 30 are interposed to be connected to the deck base 40, a spindle motor 21 which is mounted in the deck plate 20 and provides a rotating force to a disk 1, a turntable 23 which is connected to a rotating axis 22 of the spindle motor 21 and on which the disk 1 is placed, a disk clamper 10 which is mounted in an upper portion of the housing so as to be opposite to the turntable 23 and clamps the disk 1 on the turntable 23, and an optical pickup 25 which is mounted to be transferred to the deck plate 20 in a direction of a radius of the disk 1 and performs a recording/reproducing operation.
FIG. 2 shows a partial cross-sectional view of the disk player shown in FIG. 1. The disk 1, which is placed on the turntable 23, is clamped between the turntable 23 and the disk clamper 10, and is rotated with the turntable 23 and the disk camper 10 as the spindle motor 21 rotates. During the rotation of the disk 1, the optical pickup 25 performs a recording/reproducing operation on a recording surface of the disk 1. A magnet 23a and a back yoke 23b are mounted in the turntable 23, and yokes 10a are mounted in the disk clamper 10. The disk 1 is clamped by a combination of magnetic forces of the yokes 10a. 
The above disk clamping structure is based on a premise that a disk to be clamped has a uniform thickness of 1.2 mm. That is, since most disks used in a disk player have a thickness of 1.2 mm, the magnet 23a and the yokes 23b and 10a of the turntable 23 and the disk clamper 10 are designed to clamp the disks having the thickness of 1.2 mm.
Recently, however, with production of disks having high density and disk players having smaller and thinner dimensions, various changes in a disk thickness are expected and modified disks with different thicknesses have been already produced. Where a thickness of a disk is changed, it is difficult for the conventional clamping structure to accommodate the disk because a distance between the magnet 23a and the yoke 10a, which provide a clamping force, is changed. Accordingly, if the disk is thicker than 1.2 mm, the clamping force decreases, and the disk may be separated from the clamping structure of the disk player. On the other hand, if the disk is thinner than 1.2 mm, the clamping force increases, and the disk may not be smoothly released from the clamping structure of the disk player. Therefore, in the conventional clamping structure, it is very difficult to set an appropriate clamping force to cover a broad range of a thickness variation available among the disks.
Thus, there is a need for a disk clamping apparatus having a structure which reduces a variation in a clamping force caused by disks having a thickness variation, that is, different thicknesses.
Accordingly, it is an object of the present invention to provide a disk clamping apparatus for a disk player, which suppresses a variation in a clamping force caused by a variation in thickness of disks.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
To achieve the above and other objects of the present invention, there is provided a disk clamping apparatus for a disk player, comprising a turntable for receiving a disk thereon, a disk clamper which clamps the disk placed on the turntable, and first and second magnetic bodies which are mounted in the turntable and the disk clamper, respectively, and provide a clamping force to the disk by acting a reciprocal magnetic force on the turntable and the disk clamper. The first and second magnetic bodies are positioned opposite to and partially overlap each other.